Molecular genetic study of families with Primary Congenital Glaucoma (PCG) can be used to identify the chromosomal site of the disease gene. Recent availability of 1-5 cM maps of human chromosomes together with new advances in positional mapping and cloning has provided an ample opportunity for locating the chromosomal site of the PCG gene. The obtained knowledge from mapping and eventual cloning of the PCG gene may help to clarify the etiology of this condition and may be used to obtain further information about the biology and function of the human eye. Dr. Mansoor Sarfarazi and his associates have now identified a number of genetic loci in different forms of glaucoma, including primary congenital glaucoma, juvenile-onset primary open angle glaucoma, and late-onset chronic open angle glaucoma. Mutations in Cytochrome P450-1B1 and the Trabecular meshwork Inducible Glucocorticoid-Response Protein (TIGR) genes have been identified, including two loci for Primary Congenital Glaucoma and four loci for adult onset Primary Open Angle Glaucoma. Dr. Sarfarazi will continue to carry out studies on familial and congenital glaucoma, but the main thrust of his proposal is now to identify the specific abnormalities in late-onset glaucoma in a series of patients being treated in the community, in order to estimate the prevalence of different mutations in the general population.